This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. We are using a novel surface biotinylation technique to affinity label proteins on the surface membrane and flagellar pockets of trypanosoma brucei. We then use mass spectrometry to identify proteins enriched via the biotin tag. While we have shown that the procedure is working well, it is now necessary to deplete the sample of the dominant Variant Surface Glycoprotein fraction so that we can decrease this unwanted background and increase the attainable dynamic range for this surface proteome elucidation.